The present invention relates to ground surface cover systems used for erosion control, and more particularly to a ground surface cover system featuring interlocking elements flexibly locked by a flexible interlocking joint, used for erosion control, and a corresponding method.
Erosion is a process involving the movement of earthy or rock material along a ground surface as result of natural processes including rain, wind, earthquakes and related movements in the ground, or man made processes such as water redistribution or the formation of artificial bodies of water, which are capable of moving earthy or rock material along the upper surface of the ground. Ordinarily, it is desirable to control erosion at elevated or inclined locations such as along roadsides, edges around bodies of water, for example, reservoirs, rivers, and lakes, and bridge to ground connections, where erosion is known to cause structural and environmental damage.
Currently, commonly used methods of effectively controlling erosion involve the placement of a ground cover on top of and along the surface of interest, of an area extending the region of desired erosion control. The main objective of placing ground cover is to adequately control or minimize the movement of earthy or rock material along the surface of the ground, whatever the cause of the movement. In terms of functionality, there are several important properties for a ground surface cover system to have in order to be effective. Foremost, an effective ground surface cover system needs to be made of sufficient strength and long term stability to withstand one or more of the elements causing erosion processes such as water, water flow, and ground movement, over long periods of time, i.e., years. At locations where water flow is involved in the erosion process, it is desirable for a ground surface covering to withstand, and allow for, efficient patterns of water flow and water distribution along the covered surface or ground. At locations where ground movement is involved in the erosion process, for example, involving cavity or protrusion formations at the ground surface, it is desirable for the ground surface cover system to horizontally, vertically, and angularly self-adjust, in a flexible way, along with ground movement, otherwise damage to the ground surface cover system may take place, thereby decreasing the effectiveness of subsequent erosion control at such locations. Instead of, or, in addition to self-adjustment, for the same reason, it is desirable for a ground surface cover system to be manually adjustable, or flexible, according to need. Hereinafter, the terms flexible and flexibility refer to horizontal, vertical, and/or angular motion or movement, whereby such motion or movement is of a ground surface cover system in general, of interlocking elements of a ground surface cover system, or, of the interlocking joint of the elements, in particular.
An additional, but optional, desired attribute of a ground surface cover system relates to landscape, involving the presence of spaces throughout the ground surface cover system enabling botanic growth. This attribute may or may not have functional importance to the ground surface cover system, depending upon the actual causes and parameters of an erosion process at a particular location, i.e., the presence of botanic growth throughout a ground surface cover system can affect patterns of water flow, movement of ground, and movement of the ground surface cover system itself. Other important attributes of a suitable ground cover system are economic based, whereby manufacturing and installation need to be feasible, practical, and of reasonable costs. Other attributes include the extent to which a ground surface cover system is replaceable and reusable either at a same location, at a different location, or both.
Several different types of ground surface cover systems are in common use. In addition to simply partially or completely covering the selected area of ground surface requiring erosion control with a multitude of removable individual stones, four main categories are ordinarily referred to with respect to ground surface cover systems, i.e., single cast structures, multi-cast structures, xe2x80x98gabionxe2x80x99 structures, and combination structures. Single cast ground surface cover systems are based on permanently covering the selected area of ground surface requiring erosion control with a layer of concrete alone, or, with a layer of concrete containing a dispersion of stones. Optional metal reinforcements internal to the cover material may be used throughout selected portions of the ground surface cover system. Multi-cast ground surface cover systems are based on the placement of a multitude of, removable, individual, geometrically formed, elements or blocks, usually made from concrete, which partially or incompletely cover the selected area of ground surface requiring erosion control. Gabion ground surface cover systems are based on the placement of gabion structures, featuring a continuous or discontinuous network or web like structured system of metal baskets or cages of specified geometries, dimensions, and rigidity, filled with a chosen density of loose, non-cemented stones. Combination ground surface cover systems are based on the placement of a plastic matting featuring concrete casting modules, typically of a honeycomb like geometry, upon the ground, and casting, on-site, the concrete modules. Individual concrete modules are relatively near to, but are not in contact with, each other.
Multi-cast ground surface cover systems may be further classified into two different types, i.e., systems based on interconnecting elements or locks, and systems based on interlocking elements or blocks. Hereinafter, interconnecting refers to the state or configuration of elements or blocks placed side-to-side or adjacent to each other, thereby forming a larger non-flexible pattern of such elements or blocks, where the elements or blocks are connected, and not locked, even loosely, to each other via element to element or block to block male to female connection or mating of any sort. Hereinafter, interlocking refers to the state or configuration of elements or blocks which are placed in contact with each other via some sort of element to element or block to block male to female interlocking connection or mating, thereby forming a larger non-flexible or flexible pattern of such elements or blocks, where the elements or blocks are locked to each other. In this case, the interlocking connection or mating between any two elements or blocks forms a joint, where the joint is comprised of a male component structural feature such as a hook, protrusion, extension, barb, tongue, or nose, compatible with and interlocked to a corresponding female component structural feature such as a recess, opening, or related cutout structural feature. According to present usage, an interlocking element to element or block to block joint may be non-flexible or flexible, whereby flexibility refers to the capability of movement or turning in a horizontal or vertical direction without damaging or breaking the interlocking joint, or the elements or blocks.
In regard to multi-cast ground surface cover systems, current teachings of interlocking ground surface cover systems are based on individual elements interlocked by rigid or fixed, non-flexible joints between the elements, resulting in no degrees of freedom for vertical or horizontal movement. This characteristic of multi-cast interlocking element systems presents several significant limitations for application of such systems to erosion control. As will be shown, the system of the present invention overcomes many such limitations by featuring a flexible joint between interlocking elements of a multi-cast ground surface cover system for producing an effective erosion control system. There is a need for, and it would be useful to have a multi-cast interconnecting ground surface cover system which overcomes the limitation of non-flexibility of the system, in general, and non-flexibility of the joint of the interlocked elements, in particular, thereby resulting in a more effective erosion control system.
An ideal ground surface cover system for effective erosion control would feature all the above mentioned properties and attributes necessary for achieving the objective of adequately controlling or minimizing ground movement during a potential erosion process, including high strength and long term stability, patterns for efficient water flow and water distribution, flexible adjustment to ground movement, capability of including landscape, economic and feasible manufacturing and installation, replaceability, and reusability. It will be shown that incorporating the feature of flexibility into a ground surface cover system leads to significantly better achievement of having all of these properties and attributes of an effective erosion control system. In practice, each of the above categories of currently employed ground surface cover systems features varying degrees of limitations or shortcomings by lacking one or more of the above mentioned properties and attributes. Typically, multi-cast ground surface cover systems feature more of the above indicated properties and attributes for providing erosion control, especially with respect to the attribute of being non-permanent and removable, in contrast to single cast ground surface cover systems, and are thus more commonly employed for erosion control. Specific limitations of currently employed ground surface cover systems for erosion control follow. Each limitation is related, either directly or indirectly, to the absence of the feature of flexibility of the ground surface cover system as a whole, or to the absence of the feature of flexibility of the interlocking joint between the two elements.
For single cast ground surface cover systems, with respect to distribution of water flow, once a single cast ground surface cover system is installed on-site, the general characteristics of water flow are essentially fixed, i.e., random top to bottom flow, according to the single cast structure, and depend only upon variation in the influences causing erosion, for example, strength and velocities of rain and/or wind acting upon the ground surface cover. With respect to flexibility or adjustment to ground movement, by the very nature of a single cast ground surface cover system, there is none. That is, by sufficient forces in the ground causing cavity or protrusion formation at the ground surface, a single cast ground cover system becomes damaged, requiring on-site repair of the local and surrounding area of the single component ground surface cover which has either fallen into the cavity or protrudes from the surface. With respect to landscape, by the very nature of a single cast ground surface cover system covering the entirety of a given ground surface area, there is no space left for practically including any kind of ground landscape such as botanical growth. With respect to installation, inherently, single cast ground surface cover systems involve substantial on-site work relating to the placement of stones and casting of cement. With respect to reusability, inherently, single cast ground surface cover systems represent a one time installation, whereby, it would be extremely work intensive and economically unfeasible to remove or replace parts of the casted mixture of stones and cement.
For gabion structure ground surface cover systems, degree of limitation or shortcoming of a given property or attribute is directly related to the parameters of the system, including for instance extent or area, dimensions, and density, of the gabion structures lying on and rising above the ground surface. Gabion structures are generally rigid with respect to forces exerted by water flow or ground movement. As such, gabion ground surface cover systems provide limited control of water flow and distribution, which are based primarily on random top to bottom water flow through the stones contained within the metal baskets or cages. Depending upon stone density within the baskets or cages, over long periods of time, the stones contained within the baskets or cages of gabion structures are expected to shift, possibly leaving the baskets or cages, and may accumulate along an inclined area of potential erosion, due to gravity and influences of rainfall and wind shear, thereby causing changes in the overall gabion structure, possibly adversely affecting the efficiency of such an erosion control system. Installation of gabion structures for erosion control is ordinarily labor intensive and therefore costly, compared to installation of other erosion control systems. Moreover, as the baskets or cages of gabion structures are of metal, they are prone to corrosion following exposure to water, where the extent of corrosion depends upon the quality of metal used. Either using high quality corrosion resistant metal for the baskets or cages, or replacing baskets or cages as they corrode, clearly increases the cost of using gabion ground surface cover systems for erosion control.
Combination ground surface cover systems, based on the placement of a plastic matting, upon the ground, featuring a network of individual modules of casted concrete, is limited in several ways. Once cast, the network of concrete modules is essentially permanently fixed and non-flexible with respect to control of water flow, water distribution, and adjustment to ground movement. Moreover, since the system is based on having plastic matting covering the ground of interest, there is limited accommodation for the addition of botanic landscape. Combination erosion control systems are also significantly limited due to the need for on-site casting. In this case, typically, the quality of concrete and of the casted concrete modules are significantly less than that of multi-cast ground surface cover systems featuring concrete elements manufactured off-site and transported to the chosen site for installation. Moreover, the plastic matting and concrete modules of combination ground surface cover systems are not readily amenable to replacement or reuse.
Multi-cast interconnecting, i.e., not interlocking, element ground surface cover systems have the significant limitation of individual elements potentially being uplifted or submerged, in an unstable manner, during conditions of underground movements, i.e., cavity or protrusion formation, respectively. Under such conditions, there is the possibility of multiple elements of the interconnecting element system to move around, causing changes in patterns of water flow and water distribution, thereby, potentially adversely affecting effectiveness of erosion control. With respect to including landscape throughout an interconnecting element ground surface cover system by leaving spaces between elements, there is the limitation that, since the elements are not locked to each other, landscape spaces between elements must be maintained by a perimeter of elements. Moreover, future changes in landscape throughout such a system would require careful re-arrangement of several interconnecting elements, not simply by moving around one or two elements, in order to maintain overall system strength and stability for the purpose of providing erosion control. Related to this limitation of interconnecting element ground surface cover systems, is that of limited replaceability of individual elements. Again, since elements of an interconnecting element system are not locked to each other, moving any given element affects positioning and stability of its neighboring elements.
Multi-cast interlocking, i.e., not interconnecting, element ground surface cover systems, featuring non-flexible joints, have the potential of elements being damaged or broken under conditions of ground cavity or protrusion formation, due to the rigid nature of the fixed joints between the individual elements, especially for elements made of concrete. As a result of this, patterns of water flow and distribution are likely to change, thereby affecting erosion control effectiveness in an unpredictable manner. Additionally, with respect to water flow and distribution, as an example, placement of a rigid hollow honeycomb like or other hollow polygonal multi-cast interlocking structure at a location of erosion results in inefficient and poor control of water distribution and water flow during rainfall, whereby, water accumulates inside the honeycombs or polygonal structures, potentially leading to excessive wetting of the ground underneath the ground surface cover, with minimal possibility of water flow from top to bottom of the ground surface covering, except under flooding conditions of the individual honeycombs or polygonal structures. Another significant limitation of multi-cast interlocking element ground surface cover systems is that individual elements of such a systems are not readily replaceable, as several interlocked elements need to be removed one at a time before removing a particular element, due to the linked structure of interlocking element systems.
Based on limitations of currently employed ground surface cover systems, there is thus a need for, and it would be useful to have a ground surface cover system featuring interlocking elements flexibly locked by a flexible interlocking joint, used for erosion control, and a corresponding method. Such a system and corresponding method would overcome all of the above indicated limitations regarding effective erosion control.
Specific examples of multi-cast interconnecting ground surface cover systems currently available are those manufactured by Unglehrt GMBH and Co., Gronenbach-Zell, Germany; Franz Carl Nudling, Fulda, Germany; and Kasper Rockelein KG, Wachenroth, Germany. Each of these currently available ground surface cover systems has the above described limitations with respect to erosion control.
The present invention relates to ground surface cover systems used for erosion control, and specifically to a ground surface cover system featuring interlocking elements flexibly locked by a flexible interlocking joint, and a corresponding method, used for erosion control. There is substantial prior art regarding elements, systems, and methods based on, or including, interlocking elements for construction of floors, panels, and load bearing surfaces such as roads or airplane landing mats. However, none of the following indicated prior art refers to erosion control of a ground surface, or includes the important feature of having directional, i.e., vertical or horizontal, flexibility of the system, or of interlocking elements flexibly locked by a flexible joint. Moreover, prior art relating to elements, systems and methods featuring interlocking elements teach about rigidity or non-flexibility of the interlocking element joints, thereby preventing vertical or horizontal movement of parts of an entire system or of the individual elements. Furthermore, interlocking elements and systems of interlocking elements taught about in the following prior art are preferably made from wood, metal, polymer, composite material, or combinations thereof, and not of concrete which is preferably used for making ground surface cover systems for erosion control.
One teaching, U.S. Pat. No. 5,580,191 issued to Egan, describes a retaining wall, preferably for marine use, featuring interconnecting and interlocking elements, used for erosion control along a vertical wall adjacent to a body of water. The following prior art relates to flooring or paneling elements, systems or methods based on, or including, non-flexible interlocking elements: U.S. Pat. No. 5,797,237 issued to Finkell, Jr.; U.S. Pat. No. 4,426,820 issued to Terback et al.; U.S. Pat. No. 4,037,377 issued to Howell et al.; and U.S. Pat. No. 2,740,167 issued to Rowley. The following prior art relates to elements, systems, and methods based on, or including, non-flexible interlocking elements for constructing load bearing surfaces such as roads and airplane landing mats: U.S. Pat. No. 3,859,000 issued to Webster; U.S. Pat. No. 3,572,224 issued to Perry; U.S. Pat. No. 3,385,182 issued to Harvey; U.S. Pat. No. 3,301,147 issued to Clayton et al.; and U.S. Pat. No. 1,371,856 issued to Cade.
The present invention relates to a ground surface cover system featuring interlocking elements flexibly locked by a flexible interlocking joint, and a corresponding method used for erosion control.
The ground surface cover system of the present invention introduces the important property of flexibility to the utilization of multi-cast interlocking elements for erosion control. The flexible interlocking joint of the present invention is featured with a corresponding preferred method of mechanically engaging two interlocking elements to each other, and is extended to a preferred method of forming a system of a ground surface cover featuring different patterns of interlocking elements to be used for ground surface erosion control. Several additional specific features of the interlocking elements, further enabling the ground surface cover system of the present invention for erosion control, are provided.
The ground surface cover system and method of the present invention serve as significant improvements over currently used ground surface cover systems and methods used for erosion control. The system and method of the present invention would result in overcoming each of the above indicated limitations regarding effective erosion control, by featuring properties and attributes necessary for achieving the main objective of effectively controlling or minimizing ground movement during a potential erosion process, including high strength and long term stability, patterns for efficient water flow and water distribution, flexible adjustment to ground movement, capability of including landscape, economic and feasible manufacturing and installation, replaceability, and reusability.
According to the present invention, there is provided a ground surface cover system for use in erosion control of a ground surface, the ground surface cover system comprising at least one layer upon the ground surface of a plurality of interlocking elements, wherein opposing ends of a pair of opposing interlocking elements are flexibly interlocked by a flexible interlocking joint, the flexible interlocking joint defining mechanical engagement of an interlocking element tongue transversely extending outward from one opposing end of a first interlocking element of the pair to an interlocking element channel transversely extending outward from one opposing end of a second interlocking element of the pair.
According to the present invention, there is provided a method of erosion control of a ground surface, the method comprising the steps of: (a) providing the ground surface to be erosion controlled; and (b) covering the ground surface with at least one layer of a plurality of interlocking elements, wherein opposing ends of a pair of opposing interlocking elements are flexibly interlocked by a flexible interlocking joint, the flexible interlocking joint defining mechanical engagement of an interlocking element tongue transversely extending outward from one opposing end of a first interlocking element of the pair to an interlocking element channel transversely extending outward from one opposing end of a second interlocking element of the pair.
According to the present invention, there is provided a flexible interlocking joint of interlocking elements for use in a ground surface cover for erosion control of a ground surface, the flexible interlocking joint comprising an interlocking element tongue transversely extending outward from one opposing end of a first interlocking element of a pair of the interlocking elements mechanically engaged to an interlocking element channel transversely extending outward from one opposing end of a second interlocking element of the pair of the interlocking elements.